요청 메소드

// GET // - /method?name=김조은&age=20 // - 요청 파라미터 : name, age protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { try { // 요청 String name = request.getParameter("name"); int age = Integer.parseInt(request.getParameter("age")); System.out.println("name : " + name); System.out.println("age : " + age); // 응답 response.setContentType("text/html; charset=UTF-8"); PrintWriter writer = response.getWriter(); writer.println("<h1>name : " + name + "</h1>"); writer.println("<h1>age : " + age + "</h1>"); writer.flush(); // 출력 바로 보내기 } catch (Exception e) { System.err.println("파라미터가 올바르지 않습니다."); } }

// POST // - /method // - body : username, password // * // Content-Type : application/x-www-form-urlencoded 경우 폼요청으로 인식하고 // request.getParameter()를 호출하면 본문(body)에서 데이터를 가져온다. // * // Content-Type : multipart/form-data 의 경우는 // request.getParameter() 로 전달된 파라미터를 가져올 수 없다!!! // request.getPart("file") 로 전달된 파일 데이터를 가져와야한다. protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 요청 String username = request.getParameter("username"); String password = request.getParameter("password"); System.out.println("username : " + username); System.out.println("password : " + password); // 응답 response.setContentType("text/html; charset=UTF-8"); PrintWriter writer = response.getWriter(); writer.println("<h1>아이디 : " + username + "</h1>"); writer.println("<h1>비밀번호 : " + password + "</h1>"); }

// PUT // - /method // - 컨텐츠 타입 : JSON // - 요청 본문(body) // {"no" : "1", "title" : "제목", "content" : "내용"} protected void doPut(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 요청 (JSON -> Map) ObjectMapper mapper = new ObjectMapper(); ServletInputStream sis = request.getInputStream(); Map<String, Object> map = mapper.readValue(sis, new TypeReference<Map<String, Object>>() {}); String no = (String) map.get("no"); String title = (String) map.get("title"); String content = (String) map.get("content"); System.out.println("no : " + no); System.out.println("title : " + title); System.out.println("content : " + content); // 응답 response.setContentType("text/html; charset=UTF-8"); PrintWriter writer = response.getWriter(); writer.println("<h1>no : " + no + "</h1>"); writer.println("<h1>title : " + title + "</h1>"); writer.println("<h1>content : " + content + "</h1>"); }

// DELETE // - /method?no=10 protected void doDelete(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String noString = request.getParameter("no"); int no = 0; try { no = Integer.parseInt(noString); } catch (Exception e) { System.err.println("유효하지 않은 번호입니다."); } response.setContentType("text/plain; charset=UTF-8"); PrintWriter writer = response.getWriter(); writer.println(no + "번 글을 삭제하였습니다."); }

package method; import java.io.IOException; import java.io.PrintWriter; import java.util.Map; import com.fasterxml.jackson.core.type.TypeReference; import com.fasterxml.jackson.databind.ObjectMapper; import jakarta.servlet.ServletException; import jakarta.servlet.ServletInputStream; import jakarta.servlet.annotation.WebServlet; import jakarta.servlet.http.HttpServlet; import jakarta.servlet.http.HttpServletRequest; import jakarta.servlet.http.HttpServletResponse; @WebServlet("/method") public class MethodServlet extends HttpServlet { private static final long serialVersionUID = 1L; // GET protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { try { String name = request.getParameter("name"); int age = Integer.parseInt(request.getParameter("age")); System.out.println("name : " + name); System.out.println("age : " + age); response.setContentType("text/html; charset=UTF-8"); PrintWriter writer = response.getWriter(); writer.println("<h1>name : " + name + "</h1>"); writer.println("<h1>age : " + age + "</h1>"); writer.flush(); } catch (Exception e) { System.err.println("파라미터가 올바르지 않습니다."); } } // POST protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String username = request.getParameter("username"); String password = request.getParameter("password"); System.out.println("username : " + username); System.out.println("password : " + password); response.setContentType("text/html; charset=UTF-8"); PrintWriter writer = response.getWriter(); writer.println("<h1>아이디 : " + username + "</h1>"); writer.println("<h1>비밀번호 : " + password + "</h1>"); } // PUT protected void doPut(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ObjectMapper mapper = new ObjectMapper(); ServletInputStream sis = request.getInputStream(); Map<String, Object> map = mapper.readValue(sis, new TypeReference<Map<String, Object>>() {}); String no = (String) map.get("no"); String title = (String) map.get("title"); String content = (String) map.get("content"); System.out.println("no : " + no); System.out.println("title : " + title); System.out.println("content : " + content); response.setContentType("text/html; charset=UTF-8"); PrintWriter writer = response.getWriter(); writer.println("<h1>no : " + no + "</h1>"); writer.println("<h1>title : " + title + "</h1>"); writer.println("<h1>content : " + content + "</h1>"); } // DELETE protected void doDelete(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String noString = request.getParameter("no"); int no = 0; try { no = Integer.parseInt(noString); } catch (Exception e) { System.err.println("유효하지 않은 번호입니다."); } response.setContentType("text/plain; charset=UTF-8"); PrintWriter writer = response.getWriter(); writer.println(no + "번 글을 삭제하였습니다."); } }